Field of the Invention
The present invention relates to a communication apparatus, a computer readable storage medium, and a control method of the communication apparatus, and particularly to, for example, a communication apparatus that executes wireless communication in compliance with the IEEE802.11n specification, a computer readable storage medium, and a control method of the communication apparatus.
Description of the Related Art
In recent years, a wireless LAN conforming to the IEEE802.11 specification has been widely used. In a wireless LAN, a base station called an access point (to be referred to as an AP hereinafter) forms a network called a BSS (Basic Service Set), and communication is performed when a station (to be referred to as an STA hereinafter) connects to this network. In recent years, devices conforming to the IEEE802.11n specification which aims to speed up the wireless LAN have become widely used.
In addition to a mode (to be referred to as a 20 MHz mode hereinafter) of operating in a 20 MHz channel width, which is the same channel width as that used the related art, the IEEE802.11n specification optionally supports a mode (to be referred to as a 40 MHz mode hereinafter) of operating in a 40 MHz channel width, which is twice the size of the channel width of the related art. Although the use of a 40 MHz channel width can implement communication with twice the throughput, interference occurs more easily since wireless channels overlap in the 2.4 GHz range and the communication is susceptible to the influence from a neighboring BSS. In addition, when communication is executed in a channel width of 40 MHz, frame collision frequently occurs since the carrier signal from a wireless device which does not conform to the IEEE802.11n specification cannot be detected.
Hence, an OBSS (Overlapping Basic Service Set) scan has been defined in the IEEE802.11n specification. An OBSS scan is performed as follows.
An STA that operates in the 40 MHz mode periodically scans a neighboring network (BSS). If a BSS that does not conform to the IEEE802.11n specification or a BSS that does not permit the 40 MHz mode is detected by the scan, the STA transmits a report to a connection-destination AP. The AP which received the report stops operating in the 40 MHz mode and switches over to a wireless network supporting only the 20 MHz mode. The OBSS scan is implemented in the STA which operates by the 40 MHz mode in the 2.4 GH range.
Japanese Patent Laid-Open No. 2016-149648 discloses a technique for preventing the deterioration of communication quality due to a channel switchover by an OBSS scan.
However, among communication apparatuses that can concurrently execute the infrastructure mode and the P2P mode, there is a communication apparatus that implements an STA function and an AP function by a single wireless chip and a single antenna for the purpose of cost reduction. In this case, since such a communication apparatus cannot concurrently receive a plurality of channels, the frequency band channels and the channel widths to be used in the infrastructure mode and the P2P mode need to be the same.
Furthermore, since the AP function incorporated in the communication apparatus is a simple AP implemented by software, its function and performance are restricted compared to those of a general AP dedicated device. More specifically, the communication apparatus may lack a function that automatically searches for a free channel, a function that dynamically switches over between channel widths, and the like. In such case, AP-side function of the OBSS scan cannot be supported.
On the other hand, the image data size handled by a mobile terminal such as a smartphone is increasing. Hence, a higher speed communication is required when the data of an image captured by the mobile terminal is to be transferred via the wireless LAN and printed by an MFP.